A large number of light sources (such as, light emitting diodes) have been used in a conventional indicator displaying device for a vehicle. According to an instrumental device, for example, as disclosed in Japanese Patent No. 3301077 (FIGS. 4 and 5), not only an indicator but also a displaying portion at a front panel surface is illuminated by light emitted from a light source, so as to reduce a number of light sources and thereby to reduce cost for the indicator displaying device.
More in detail, according to the instrumental device of the above prior art (JP Patent No. 3301077), a first reflecting portion is arranged at a position close to an opening of a front panel so as to reflect light from the light source toward an outer peripheral side. In addition, a second reflecting portion is arranged so as to further reflect the light reflected from the first reflecting portion toward a displaying portion of the front panel. The displaying portion of the front panel is illuminated by the light, which is reflected by the first and second reflecting portions and passes through such displaying portion.
According to the instrumental device of the above prior art (JP Patent No. 3301077), a portion of the front panel neighboring to the opening is generally interposed between other related members, so that the front panel is fixed to a housing. For example, according to another prior art, as disclosed in Japanese Utility Model Publication No. H05-28491, a dial plate is interposed between a light guiding plate and a fixing member, which is inserted into an opening of the dial plate. A rotating shaft of an indicator passes through the opening of the dial plate. In addition, according to a further prior art, for example, as disclosed in Japanese Patent Publication No. 2009-198349, a display panel is held between a housing and a fixing member, which is inserted into an opening of the display panel.
According to the above prior art (JP Patent No. 3301077), a number of light sources for illuminating the displaying portion formed in the front panel can be reduced. On the other hand, however, it is necessary to provide the first reflecting portion for reflecting the light toward the second reflecting portion. It is, therefore, difficult to reduce a number of parts and components for the instrumental device in this prior art. According to the other prior arts (JP UM Publication No. H05-28491 or JP Patent Publication No. 2009-198349), it is difficult to design a shape of the fixing member suitable for holding the display panel between the fixing member and the housing, because there exists a first reflecting portion provided at a position close to the opening of the display panel. On the other hand, in a case that the shape of the fixing member is so designed as to be suitable for holding the display panel between the fixing member and the housing, it may become difficult to arrange the first reflecting portion at such a position, which is suitable for reflecting the light toward the second reflecting portion. As above, it is difficult to meet both of requirements, one of which is to hold the display panel to the housing in a simple structure and the other of which is to effectively illuminate the displaying portion of the display panel.